ansible/packaging/os/yum.py

#!/usr/bin/python -tt
# -*- coding: utf-8 -*-

# (c) 2012, Red Hat, Inc
# Written by Seth Vidal <skvidal at fedoraproject.org>
# (c) 2014, Epic Games, Inc.
#
# This file is part of Ansible
#
# Ansible is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Ansible is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
#


import traceback
import os
import yum
import rpm
import platform
import tempfile
import shutil
from distutils.version import LooseVersion

try:
    from yum.misc import find_unfinished_transactions, find_ts_remaining
    from rpmUtils.miscutils import splitFilename
    transaction_helpers = True
except:
    transaction_helpers = False

DOCUMENTATION = '''
---
module: yum
version_added: historical
short_description: Manages packages with the I(yum) package manager
description:
     - Installs, upgrade, removes, and lists packages and groups with the I(yum) package manager.
options:
  name:
    description:
      - "Package name, or package specifier with version, like C(name-1.0). When using state=latest, this can be '*' which means run: yum -y update. You can also pass a url or a local path to a rpm file.  To operate on several packages this can accept a comma separated list of packages or (as of 2.0) a list of packages."
    required: true
    default: null
    aliases: []
  exclude:
    description:
      - "Package name(s) to exclude when state=present, or latest"
    required: false
    version_added: "2.0"
    default: null
  list:
    description:
      - Various (non-idempotent) commands for usage with C(/usr/bin/ansible) and I(not) playbooks. See examples.
    required: false
    default: null
  state:
    description:
      - Whether to install (C(present), C(latest)), or remove (C(absent)) a package.
    required: false
    choices: [ "present", "latest", "absent" ]
    default: "present"
  enablerepo:
    description:
      - I(Repoid) of repositories to enable for the install/update operation.
        These repos will not persist beyond the transaction.
        When specifying multiple repos, separate them with a ",".
    required: false
    version_added: "0.9"
    default: null
    aliases: []

  disablerepo:
    description:
      - I(Repoid) of repositories to disable for the install/update operation.
        These repos will not persist beyond the transaction.
        When specifying multiple repos, separate them with a ",".
    required: false
    version_added: "0.9"
    default: null
    aliases: []

  conf_file:
    description:
      - The remote yum configuration file to use for the transaction.
    required: false
    version_added: "0.6"
    default: null
    aliases: []

  disable_gpg_check:
    description:
      - Whether to disable the GPG checking of signatures of packages being
        installed. Has an effect only if state is I(present) or I(latest).
    required: false
    version_added: "1.2"
    default: "no"
    choices: ["yes", "no"]
    aliases: []

  update_cache:
    description:
      - Force updating the cache. Has an effect only if state is I(present)
        or I(latest).
    required: false
    version_added: "1.9"
    default: "no"
    choices: ["yes", "no"]
    aliases: []

notes:
  - When used with a loop of package names in a playbook, ansible optimizes
    the call to the yum module.  Instead of calling the module with a single
    package each time through the loop, ansible calls the module once with all
    of the package names from the loop.
  - In versions prior to 1.9.2 this module installed and removed each package
    given to the yum module separately. This caused problems when packages
    specified by filename or url had to be installed or removed together. In
    1.9.2 this was fixed so that packages are installed in one yum
    transaction. However, if one of the packages adds a new yum repository
    that the other packages come from (such as epel-release) then that package
    needs to be installed in a separate task. This mimics yum's command line
    behaviour.
# informational: requirements for nodes
requirements: [ yum ]
author:
    - "Ansible Core Team"
    - "Seth Vidal"
'''

EXAMPLES = '''
- name: install the latest version of Apache
  yum: name=httpd state=latest

- name: remove the Apache package
  yum: name=httpd state=absent

- name: install the latest version of Apache from the testing repo
  yum: name=httpd enablerepo=testing state=present

- name: install one specific version of Apache
  yum: name=httpd-2.2.29-1.4.amzn1 state=present

- name: upgrade all packages
  yum: name=* state=latest

- name: install the nginx rpm from a remote repo
  yum: name=http://nginx.org/packages/centos/6/noarch/RPMS/nginx-release-centos-6-0.el6.ngx.noarch.rpm state=present

- name: install nginx rpm from a local file
  yum: name=/usr/local/src/nginx-release-centos-6-0.el6.ngx.noarch.rpm state=present

- name: install the 'Development tools' package group
  yum: name="@Development tools" state=present
'''

# 64k.  Number of bytes to read at a time when manually downloading pkgs via a url
BUFSIZE = 65536

def_qf = "%{name}-%{version}-%{release}.%{arch}"

def yum_base(conf_file=None):

    my = yum.YumBase()
    my.preconf.debuglevel=0
    my.preconf.errorlevel=0
    if conf_file and os.path.exists(conf_file):
        my.preconf.fn = conf_file
    if os.geteuid() != 0:
        if hasattr(my, 'setCacheDir'):
            my.setCacheDir()
        else:
            cachedir = yum.misc.getCacheDir()
            my.repos.setCacheDir(cachedir)
            my.conf.cache = 0

    return my

def ensure_yum_utils(module):

    repoquerybin = module.get_bin_path('repoquery', required=False)

    if module.params['install_repoquery'] and not repoquerybin and not module.check_mode:
        yum_path = module.get_bin_path('yum')
        if yum_path:
            rc, so, se = module.run_command('%s -y install yum-utils' % yum_path)
        repoquerybin = module.get_bin_path('repoquery', required=False)

    return repoquerybin

def po_to_nevra(po):

    if hasattr(po, 'ui_nevra'):
        return po.ui_nevra
    else:
        return '%s-%s-%s.%s' % (po.name, po.version, po.release, po.arch)

def is_installed(module, repoq, pkgspec, conf_file, qf=def_qf, en_repos=None, dis_repos=None, is_pkg=False):
    if en_repos is None:
        en_repos = []
    if dis_repos is None:
        dis_repos = []
    if not repoq:

        pkgs = []
        try:
            my = yum_base(conf_file)
            for rid in dis_repos:
                my.repos.disableRepo(rid)
            for rid in en_repos:
                my.repos.enableRepo(rid)
                
            e, m, u = my.rpmdb.matchPackageNames([pkgspec])
            pkgs = e + m
            if not pkgs:
                pkgs.extend(my.returnInstalledPackagesByDep(pkgspec))
        except Exception, e:
            module.fail_json(msg="Failure talking to yum: %s" % e)

        return [ po_to_nevra(p) for p in pkgs ]

    else:

        cmd = repoq + ["--disablerepo=*", "--pkgnarrow=installed", "--qf", qf, pkgspec]
        rc, out, err = module.run_command(cmd)
        if not is_pkg:
            cmd = repoq + ["--disablerepo=*", "--pkgnarrow=installed", "--qf", qf, "--whatprovides", pkgspec]
            rc2, out2, err2 = module.run_command(cmd)
        else:
            rc2, out2, err2 = (0, '', '')
            
        if rc == 0 and rc2 == 0:
            out += out2
            return [p for p in out.split('\n') if p.strip()]
        else:
            module.fail_json(msg='Error from repoquery: %s: %s' % (cmd, err + err2))
            
    return []

def is_available(module, repoq, pkgspec, conf_file, qf=def_qf, en_repos=None, dis_repos=None):
    if en_repos is None:
        en_repos = []
    if dis_repos is None:
        dis_repos = []

    if not repoq:

        pkgs = []
        try:
            my = yum_base(conf_file)
            for rid in dis_repos:
                my.repos.disableRepo(rid)
            for rid in en_repos:
                my.repos.enableRepo(rid)

            e,m,u = my.pkgSack.matchPackageNames([pkgspec])
            pkgs = e + m
            if not pkgs:
                pkgs.extend(my.returnPackagesByDep(pkgspec))
        except Exception, e:
            module.fail_json(msg="Failure talking to yum: %s" % e)
            
        return [ po_to_nevra(p) for p in pkgs ]

    else:
        myrepoq = list(repoq)
                 
        r_cmd = ['--disablerepo', ','.join(dis_repos)]
        myrepoq.extend(r_cmd)

        r_cmd = ['--enablerepo', ','.join(en_repos)]
        myrepoq.extend(r_cmd)

        cmd = myrepoq + ["--qf", qf, pkgspec]
        rc,out,err = module.run_command(cmd)
        if rc == 0:
            return [ p for p in out.split('\n') if p.strip() ]
        else:
            module.fail_json(msg='Error from repoquery: %s: %s' % (cmd, err))

    return []

def is_update(module, repoq, pkgspec, conf_file, qf=def_qf, en_repos=None, dis_repos=None):
    if en_repos is None:
        en_repos = []
    if dis_repos is None:
        dis_repos = []

    if not repoq:

        retpkgs = []
        pkgs = []
        updates = []

        try:
            my = yum_base(conf_file)
            for rid in dis_repos:
                my.repos.disableRepo(rid)
            for rid in en_repos:
                my.repos.enableRepo(rid)

            pkgs = my.returnPackagesByDep(pkgspec) + my.returnInstalledPackagesByDep(pkgspec)
            if not pkgs:
                e,m,u = my.pkgSack.matchPackageNames([pkgspec])
                pkgs = e + m
            updates = my.doPackageLists(pkgnarrow='updates').updates 
        except Exception, e:
            module.fail_json(msg="Failure talking to yum: %s" % e)

        for pkg in pkgs:
            if pkg in updates:
                retpkgs.append(pkg)
            
        return set([ po_to_nevra(p) for p in retpkgs ])

    else:
        myrepoq = list(repoq)
        r_cmd = ['--disablerepo', ','.join(dis_repos)]
        myrepoq.extend(r_cmd)

        r_cmd = ['--enablerepo', ','.join(en_repos)]
        myrepoq.extend(r_cmd)

        cmd = myrepoq + ["--pkgnarrow=updates", "--qf", qf, pkgspec]
        rc,out,err = module.run_command(cmd)
        
        if rc == 0:
            return set([ p for p in out.split('\n') if p.strip() ])
        else:
            module.fail_json(msg='Error from repoquery: %s: %s' % (cmd, err))
            
    return set()

def what_provides(module, repoq, req_spec, conf_file,  qf=def_qf, en_repos=None, dis_repos=None):
    if en_repos is None:
        en_repos = []
    if dis_repos is None:
        dis_repos = []

    if not repoq:

        pkgs = []
        try:
            my = yum_base(conf_file)
            for rid in dis_repos:
                my.repos.disableRepo(rid)
            for rid in en_repos:
                my.repos.enableRepo(rid)

            pkgs = my.returnPackagesByDep(req_spec) + my.returnInstalledPackagesByDep(req_spec)
            if not pkgs:
                e,m,u = my.pkgSack.matchPackageNames([req_spec])
                pkgs.extend(e)
                pkgs.extend(m)
                e,m,u = my.rpmdb.matchPackageNames([req_spec])
                pkgs.extend(e)
                pkgs.extend(m)
        except Exception, e:
            module.fail_json(msg="Failure talking to yum: %s" % e)

        return set([ po_to_nevra(p) for p in pkgs ])

    else:
        myrepoq = list(repoq)
        r_cmd = ['--disablerepo', ','.join(dis_repos)]
        myrepoq.extend(r_cmd)

        r_cmd = ['--enablerepo', ','.join(en_repos)]
        myrepoq.extend(r_cmd)

        cmd = myrepoq + ["--qf", qf, "--whatprovides", req_spec]
        rc,out,err = module.run_command(cmd)
        cmd = myrepoq + ["--qf", qf, req_spec]
        rc2,out2,err2 = module.run_command(cmd)
        if rc == 0 and rc2 == 0:
            out += out2
            pkgs = set([ p for p in out.split('\n') if p.strip() ])
            if not pkgs:
                pkgs = is_installed(module, repoq, req_spec, conf_file, qf=qf)
            return pkgs
        else:
            module.fail_json(msg='Error from repoquery: %s: %s' % (cmd, err + err2))

    return set()

def transaction_exists(pkglist):
    """ 
    checks the package list to see if any packages are 
    involved in an incomplete transaction 
    """

    conflicts = []
    if not transaction_helpers:
        return conflicts

    # first, we create a list of the package 'nvreas'
    # so we can compare the pieces later more easily
    pkglist_nvreas = []
    for pkg in pkglist:
        pkglist_nvreas.append(splitFilename(pkg))

    # next, we build the list of packages that are
    # contained within an unfinished transaction
    unfinished_transactions = find_unfinished_transactions()
    for trans in unfinished_transactions:
        steps = find_ts_remaining(trans)
        for step in steps:
            # the action is install/erase/etc., but we only
            # care about the package spec contained in the step
            (action, step_spec) = step
            (n,v,r,e,a) = splitFilename(step_spec)
            # and see if that spec is in the list of packages
            # requested for installation/updating
            for pkg in pkglist_nvreas:
                # if the name and arch match, we're going to assume
                # this package is part of a pending transaction
                # the label is just for display purposes
                label = "%s-%s" % (n,a)
                if n == pkg[0] and a == pkg[4]:
                    if label not in conflicts:
                        conflicts.append("%s-%s" % (n,a))
                    break
    return conflicts

def local_nvra(module, path):
    """return nvra of a local rpm passed in"""

    ts = rpm.TransactionSet()
    ts.setVSFlags(rpm._RPMVSF_NOSIGNATURES)
    fd = os.open(path, os.O_RDONLY)
    try:
        header = ts.hdrFromFdno(fd)
    finally:
        os.close(fd)

    return '%s-%s-%s.%s' % (header[rpm.RPMTAG_NAME], 
                            header[rpm.RPMTAG_VERSION],
                            header[rpm.RPMTAG_RELEASE],
                            header[rpm.RPMTAG_ARCH])
    
def pkg_to_dict(pkgstr):

    if pkgstr.strip():
        n,e,v,r,a,repo = pkgstr.split('|')
    else:
        return {'error_parsing': pkgstr}

    d = {
        'name':n,
        'arch':a,
        'epoch':e,
        'release':r,
        'version':v,
        'repo':repo,
        'nevra': '%s:%s-%s-%s.%s' % (e,n,v,r,a)
    }

    if repo == 'installed':
        d['yumstate'] = 'installed'
    else:
        d['yumstate'] = 'available'

    return d

def repolist(module, repoq, qf="%{repoid}"):

    cmd = repoq + ["--qf", qf, "-a"]
    rc,out,err = module.run_command(cmd)
    ret = []
    if rc == 0:
        ret = set([ p for p in out.split('\n') if p.strip() ])
    return ret

def list_stuff(module, repoquerybin, conf_file, stuff):

    qf = "%{name}|%{epoch}|%{version}|%{release}|%{arch}|%{repoid}"
    repoq = [repoquerybin, '--show-duplicates', '--plugins', '--quiet']
    if conf_file and os.path.exists(conf_file):
        repoq += ['-c', conf_file]

    if stuff == 'installed':
        return [ pkg_to_dict(p) for p in is_installed(module, repoq, '-a', conf_file, qf=qf) if p.strip() ]
    elif stuff == 'updates':
        return [ pkg_to_dict(p) for p in is_update(module, repoq, '-a', conf_file, qf=qf) if p.strip() ]
    elif stuff == 'available':
        return [ pkg_to_dict(p) for p in is_available(module, repoq, '-a', conf_file, qf=qf) if p.strip() ]
    elif stuff == 'repos':
        return [ dict(repoid=name, state='enabled') for name in repolist(module, repoq) if name.strip() ]
    else:
        return [ pkg_to_dict(p) for p in is_installed(module, repoq, stuff, conf_file, qf=qf) + is_available(module, repoq, stuff, conf_file, qf=qf) if p.strip() ]

def install(module, items, repoq, yum_basecmd, conf_file, en_repos, dis_repos):

    pkgs = []
    res = {}
    res['results'] = []
    res['msg'] = ''
    res['rc'] = 0
    res['changed'] = False
    tempdir = tempfile.mkdtemp()

    for spec in items:
        pkg = None

        # check if pkgspec is installed (if possible for idempotence)
        # localpkg
        if spec.endswith('.rpm') and '://' not in spec:
            # get the pkg name-v-r.arch
            if not os.path.exists(spec):
                res['msg'] += "No Package file matching '%s' found on system" % spec
                module.fail_json(**res)

            nvra = local_nvra(module, spec)
            # look for them in the rpmdb
            if is_installed(module, repoq, nvra, conf_file, en_repos=en_repos, dis_repos=dis_repos):
                # if they are there, skip it
                continue
            pkg = spec

        # URL
        elif '://' in spec:
            pkg = spec
            # Check if Enterprise Linux 5 or less, as yum on those versions do not support installing via url
            distribution_version = get_distribution_version()
            distribution = platform.dist()
            if distribution[0] == "redhat" and LooseVersion(distribution_version) < LooseVersion("6"):
                package = os.path.join(tempdir, str(pkg.rsplit('/', 1)[1]))
                try:
                    rsp, info = fetch_url(module, pkg)
                    f = open(package, 'w')
                    data = rsp.read(BUFSIZE)
                    while data:
                        f.write(data)
                        data = rsp.read(BUFSIZE)
                    f.close()
                    pkg = package
                except Exception, e:
                    shutil.rmtree(tempdir)
                    module.fail_json(msg="Failure downloading %s, %s" % (spec, e))

        #groups :(
        elif spec.startswith('@'):
            # complete wild ass guess b/c it's a group
            pkg = spec

        # range requires or file-requires or pkgname :(
        else:
            # most common case is the pkg is already installed and done
            # short circuit all the bs - and search for it as a pkg in is_installed
            # if you find it then we're done
            if not set(['*','?']).intersection(set(spec)):
                installed_pkgs = is_installed(module, repoq, spec, conf_file, en_repos=en_repos, dis_repos=dis_repos, is_pkg=True)
                if installed_pkgs:
                    res['results'].append('%s providing %s is already installed' % (installed_pkgs[0], spec))
                    continue
            
            # look up what pkgs provide this
            pkglist = what_provides(module, repoq, spec, conf_file, en_repos=en_repos, dis_repos=dis_repos)
            if not pkglist:
                res['msg'] += "No Package matching '%s' found available, installed or updated" % spec
                module.fail_json(**res)

            # if any of the packages are involved in a transaction, fail now
            # so that we don't hang on the yum operation later
            conflicts = transaction_exists(pkglist)
            if len(conflicts) > 0:
                res['msg'] += "The following packages have pending transactions: %s" % ", ".join(conflicts)
                module.fail_json(**res)

            # if any of them are installed
            # then nothing to do

            found = False
            for this in pkglist:
                if is_installed(module, repoq, this, conf_file, en_repos=en_repos, dis_repos=dis_repos, is_pkg=True):
                    found = True
                    res['results'].append('%s providing %s is already installed' % (this, spec))
                    break

            # if the version of the pkg you have installed is not in ANY repo, but there are
            # other versions in the repos (both higher and lower) then the previous checks won't work.
            # so we check one more time. This really only works for pkgname - not for file provides or virt provides
            # but virt provides should be all caught in what_provides on its own.
            # highly irritating
            if not found:
                if is_installed(module, repoq, spec, conf_file, en_repos=en_repos, dis_repos=dis_repos):
                    found = True
                    res['results'].append('package providing %s is already installed' % (spec))
                    
            if found:
                continue

            # if not - then pass in the spec as what to install
            # we could get here if nothing provides it but that's not
            # the error we're catching here
            pkg = spec

        pkgs.append(pkg)

    if pkgs:
        cmd = yum_basecmd + ['install'] + pkgs

        if module.check_mode:
            # Remove rpms downloaded for EL5 via url
            try:
                shutil.rmtree(tempdir)
            except Exception, e:
                module.fail_json(msg="Failure deleting temp directory %s, %s" % (tempdir, e))

            module.exit_json(changed=True, results=res['results'], changes=dict(installed=pkgs))

        changed = True

        rc, out, err = module.run_command(cmd)

        if (rc == 1):
            for spec in items:
                # Fail on invalid urls:
                if ('://' in spec and ('No package %s available.' % spec in out or 'Cannot open: %s. Skipping.' % spec in err)):
                    err = 'Package at %s could not be installed' % spec
                    module.fail_json(changed=False,msg=err,rc=1)
        if (rc != 0 and 'Nothing to do' in err) or 'Nothing to do' in out:
            # avoid failing in the 'Nothing To Do' case
            # this may happen with an URL spec.
            # for an already installed group,
            # we get rc = 0 and 'Nothing to do' in out, not in err.
            rc = 0
            err = ''
            out = '%s: Nothing to do' % spec
            changed = False

        res['rc'] = rc
        res['results'].append(out)
        res['msg'] += err

        # FIXME - if we did an install - go and check the rpmdb to see if it actually installed
        # look for each pkg in rpmdb
        # look for each pkg via obsoletes

        # Record change
        res['changed'] = changed

    # Remove rpms downloaded for EL5 via url
    try:
        shutil.rmtree(tempdir)
    except Exception, e:
        module.fail_json(msg="Failure deleting temp directory %s, %s" % (tempdir, e))

    return res


def remove(module, items, repoq, yum_basecmd, conf_file, en_repos, dis_repos):

    pkgs = []
    res = {}
    res['results'] = []
    res['msg'] = ''
    res['changed'] = False
    res['rc'] = 0

    for pkg in items:
        is_group = False
        # group remove - this is doom on a stick
        if pkg.startswith('@'):
            is_group = True
        else:
            if not is_installed(module, repoq, pkg, conf_file, en_repos=en_repos, dis_repos=dis_repos):
                res['results'].append('%s is not installed' % pkg)
                continue

        pkgs.append(pkg)

    if pkgs:
        # run an actual yum transaction
        cmd = yum_basecmd + ["remove"] + pkgs

        if module.check_mode:
            module.exit_json(changed=True, results=res['results'], changes=dict(removed=pkgs))

        rc, out, err = module.run_command(cmd)

        res['rc'] = rc
        res['results'].append(out)
        res['msg'] = err

        # compile the results into one batch. If anything is changed 
        # then mark changed
        # at the end - if we've end up failed then fail out of the rest
        # of the process

        # at this point we should check to see if the pkg is no longer present
        
        for pkg in pkgs:
            if not pkg.startswith('@'): # we can't sensibly check for a group being uninstalled reliably
                # look to see if the pkg shows up from is_installed. If it doesn't
                if not is_installed(module, repoq, pkg, conf_file, en_repos=en_repos, dis_repos=dis_repos):
                    res['changed'] = True
                else:
                    module.fail_json(**res)

        if rc != 0:
            module.fail_json(**res)

    return res

def latest(module, items, repoq, yum_basecmd, conf_file, en_repos, dis_repos):

    res = {}
    res['results'] = []
    res['msg'] = ''
    res['changed'] = False
    res['rc'] = 0
    pkgs = {}
    pkgs['update'] = []
    pkgs['install'] = []
    updates = {}
    update_all = False
    cmd = None

    # determine if we're doing an update all
    if '*' in items:
        update_all = True

    # run check-update to see if we have packages pending
    rc, out, err = module.run_command(yum_basecmd + ['check-update'])
    if rc == 0 and update_all:
        res['results'].append('Nothing to do here, all packages are up to date')
        return res
    elif rc == 100:
        available_updates = out.split('\n')
        # build update dictionary
        for line in available_updates:
            line = line.split()
            # ignore irrelevant lines
            # FIXME... revisit for something less kludgy
            if '*' in line or len(line) != 3 or '.' not in line[0]:
                continue
            else:
                pkg, version, repo = line
                name, dist = pkg.rsplit('.', 1)
                updates.update({name: {'version': version, 'dist': dist, 'repo': repo}})
    elif rc == 1:
        res['msg'] = err
        res['rc'] = rc
        module.fail_json(**res)

    if update_all:
        cmd = yum_basecmd + ['update']
    else:
        for spec in items:
            # some guess work involved with groups. update @<group> will install the group if missing
            if spec.startswith('@'):
                pkgs['update'].append(spec)
                continue
            # dep/pkgname  - find it
            else:
                if is_installed(module, repoq, spec, conf_file, en_repos=en_repos, dis_repos=dis_repos):
                    pkgs['update'].append(spec)
                else:
                    pkgs['install'].append(spec)
            pkglist = what_provides(module, repoq, spec, conf_file, en_repos=en_repos, dis_repos=dis_repos)
            # FIXME..? may not be desirable to throw an exception here if a single package is missing
            if not pkglist:
                res['msg'] += "No Package matching '%s' found available, installed or updated" % spec
                module.fail_json(**res)

            nothing_to_do = True
            for this in pkglist:
                if spec in pkgs['install'] and is_available(module, repoq, this, conf_file, en_repos=en_repos, dis_repos=dis_repos):
                    nothing_to_do = False
                    break

            if spec in pkgs['update'] and spec in updates.keys():
                nothing_to_do = False

            if nothing_to_do:
                res['results'].append("All packages providing %s are up to date" % spec)
                continue

            # if any of the packages are involved in a transaction, fail now
            # so that we don't hang on the yum operation later
            conflicts = transaction_exists(pkglist)
            if len(conflicts) > 0:
                res['msg'] += "The following packages have pending transactions: %s" % ", ".join(conflicts)
                module.fail_json(**res)

    # list of package updates
    if update_all:
        will_update = updates.keys()
    else:
        will_update = [u for u in pkgs['update'] if u in updates.keys() or u.startswith('@')]

    # check_mode output
    if module.check_mode:
        to_update = []
        for w in will_update:
            if w.startswith('@'):
                to_update.append((w, None))
                msg = '%s will be updated' % w
            else:
                to_update.append((w, '%s.%s from %s' % (updates[w]['version'], updates[w]['dist'], updates[w]['repo'])))

        res['changes'] = dict(installed=pkgs['install'], updated=to_update)

        if len(will_update) > 0 or len(pkgs['install']) > 0:
            res['changed'] = True

        return res

    # run commands
    if cmd:     # update all
        rc, out, err = module.run_command(cmd)
        res['changed'] = True
    else:
        if len(pkgs['install']) > 0:    # install missing
            cmd = yum_basecmd + ['install'] + pkgs['install']
            rc, out, err = module.run_command(cmd)
            res['changed'] = True
        else:
            rc, out, err = [0, '', '']

        if len(will_update) > 0:     # update present
            cmd = yum_basecmd + ['update'] + pkgs['update']
            rc2, out2, err2 = module.run_command(cmd)
            res['changed'] = True
        else:
            rc2, out2, err2 = [0, '', '']

    if not update_all:
        rc += rc2
        out += out2
        err += err2

    res['rc'] += rc
    res['msg'] += err
    res['results'].append(out)

    if rc:
        res['failed'] = True

    return res

def ensure(module, state, pkgs, conf_file, enablerepo, disablerepo,
           disable_gpg_check, exclude, repoq):

    yumbin = module.get_bin_path('yum')
    # need debug level 2 to get 'Nothing to do' for groupinstall.
    yum_basecmd = [yumbin, '-d', '2', '-y']

    if conf_file and os.path.exists(conf_file):
        yum_basecmd += ['-c', conf_file]
        if repoq:
            repoq += ['-c', conf_file]

    dis_repos =[]
    en_repos = []
    if disablerepo:
        dis_repos = disablerepo.split(',')
        r_cmd = ['--disablerepo=%s' % disablerepo]
        yum_basecmd.extend(r_cmd)
    if enablerepo:
        en_repos = enablerepo.split(',')
        r_cmd = ['--enablerepo=%s' % enablerepo]
        yum_basecmd.extend(r_cmd)

    if exclude:
        e_cmd = ['--exclude=%s' % exclude]
        yum_basecmd.extend(e_cmd)

    if state in ['installed', 'present', 'latest']:

        if module.params.get('update_cache'):
            module.run_command(yum_basecmd + ['makecache'])

        my = yum_base(conf_file)
        try:
            if disablerepo:
                my.repos.disableRepo(disablerepo)
            current_repos = my.repos.repos.keys()
            if enablerepo:
                try:
                    my.repos.enableRepo(enablerepo)
                    new_repos = my.repos.repos.keys()
                    for i in new_repos:
                        if not i in current_repos:
                            rid = my.repos.getRepo(i)
                            a = rid.repoXML.repoid
                    current_repos = new_repos
                except yum.Errors.YumBaseError, e:
                    module.fail_json(msg="Error setting/accessing repos: %s" % (e))
        except yum.Errors.YumBaseError, e:
            module.fail_json(msg="Error accessing repos: %s" % e)
    if state in ['installed', 'present']:
        if disable_gpg_check:
            yum_basecmd.append('--nogpgcheck')
        res = install(module, pkgs, repoq, yum_basecmd, conf_file, en_repos, dis_repos)
    elif state in ['removed', 'absent']:
        res = remove(module, pkgs, repoq, yum_basecmd, conf_file, en_repos, dis_repos)
    elif state == 'latest':
        if disable_gpg_check:
            yum_basecmd.append('--nogpgcheck')
        res = latest(module, pkgs, repoq, yum_basecmd, conf_file, en_repos, dis_repos)
    else:
        # should be caught by AnsibleModule argument_spec
        module.fail_json(msg="we should never get here unless this all"
                " failed", changed=False, results='', errors='unepected state')

    return res

def main():

    # state=installed name=pkgspec
    # state=removed name=pkgspec
    # state=latest name=pkgspec
    #
    # informational commands:
    #   list=installed
    #   list=updates
    #   list=available
    #   list=repos
    #   list=pkgspec

    module = AnsibleModule(
        argument_spec = dict(
            name=dict(aliases=['pkg'], type="list"),
            exclude=dict(required=False, default=None),
            # removed==absent, installed==present, these are accepted as aliases
            state=dict(default='installed', choices=['absent','present','installed','removed','latest']),
            enablerepo=dict(),
            disablerepo=dict(),
            list=dict(),
            conf_file=dict(default=None),
            disable_gpg_check=dict(required=False, default="no", type='bool'),
            update_cache=dict(required=False, default="no", type='bool'),
            # this should not be needed, but exists as a failsafe
            install_repoquery=dict(required=False, default="yes", type='bool'),
        ),
        required_one_of = [['name','list']],
        mutually_exclusive = [['name','list']],
        supports_check_mode = True
    )

    params = module.params

    if params['list']:
        repoquerybin = ensure_yum_utils(module)
        if not repoquerybin:
            module.fail_json(msg="repoquery is required to use list= with this module. Please install the yum-utils package.")
        results = dict(results=list_stuff(module, repoquerybin, params['conf_file'], params['list']))

    else:
        # If rhn-plugin is installed and no rhn-certificate is available on
        # the system then users will see an error message using the yum API.
        # Use repoquery in those cases.

        my = yum_base(params['conf_file'])
        # A sideeffect of accessing conf is that the configuration is
        # loaded and plugins are discovered
        my.conf
        repoquery = None
        try:
            yum_plugins = my.plugins._plugins
        except AttributeError:
            pass
        else:
            if 'rhnplugin' in yum_plugins:
                repoquerybin = ensure_yum_utils(module)
                if repoquerybin:
                    repoquery = [repoquerybin, '--show-duplicates', '--plugins', '--quiet']

        pkg = [ p.strip() for p in params['name']]
        exclude = params['exclude']
        state = params['state']
        enablerepo = params.get('enablerepo', '')
        disablerepo = params.get('disablerepo', '')
        disable_gpg_check = params['disable_gpg_check']
        results = ensure(module, state, pkg, params['conf_file'], enablerepo,
                     disablerepo, disable_gpg_check, exclude, repoquery)
        if repoquery:
            results['msg'] = '%s %s' % (results.get('msg',''), 'Warning: Due to potential bad behaviour with rhnplugin and certificates, used slower repoquery calls instead of Yum API.')

    module.exit_json(**results)

# import module snippets
from ansible.module_utils.basic import *
from ansible.module_utils.urls import *
if __name__ == '__main__':
    main()